[I] data integrity

A guarantee of the exactness and completeness of the information and the methods for processing it.

What would be the importance of the data being changed uncontrollably?

Data is attributed a high value from the point of view of integrity when their alteration, intentional or unintentional would cause serious damage to the organisation.

Likewise, data have little crucial value from the point of view of integrity when their alteration is of no concern.